This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 46 |
| 6 | 166 |
| 7 | 652 |
| 8 | 2780 |
| 9 | 12644 |
| 10 | 61136 |
| 11 | 312676 |
| 12 | 1680592 |
| 13 | 9467680 |
| 14 | 55704104 |
| 15 | 341185496 |
| 16 | 2170853456 |
| 17 | 14314313872 |
| 18 | 97620050080 |
| 19 | 687418278544 |
| 20 | 4989946902176 |
| 21 | 37286121988256 |
| 22 | 286432845428192 |
| 23 | 2259405263572480 |
| 24 | 18280749571449664 |
| 25 | 151561941235370176 |